STORM LAKE, Iowa -- Travis Foley vividly recalls his first day on the job at a recycling plant in this farming town of 9,000.

"I threw up three times," he says. Flies swarm his face and hands as he sifts raw trash on a steamy September day. "Didn't stop working, though," the 20-year-old adds. "I just stepped back and vomited in the nearest can."

Mr. Foley worked previously at a pig abattoir and reckoned he was beyond such queasiness. "But there's stuff you see here," he says, "that would make even Superman sick."

Mr. Foley belongs to a fast-growing legion of laborers who do the dirty work of keeping America clean. As state after state passes recycling laws, household garbage that once headed straight to the landfill or incinerator now often heads instead to what is known as a "materials recovery facility," or "MuRF" for short.

At "dirty MuRFs," such as Storm Lake's, workers retrieve cans, bottles and other recyclables from raw trash dumped on conveyor belts. At other facilities (there are many variations), the recyclables arrive presorted by residents into plastic bags. But the system is imperfect: The bags often burst and mix with other refuse, and they frequently contain garbage that shouldn't be there.

"We've had a lot of trouble convincing people that disposable diapers are not recyclable," says Robert Sink, a manager at the Omaha, Neb., Solid Waste Recycling Center.

There now are about 400 MuRFs nationwide--roughly triple the number in 1990--and the number appears likely to keep multiplying as states and cities strengthen recycling efforts. Some MuRFs employ prisoners at 40 to 75 cents an hour plus time off their sentences; others hire the mentally handicapped. Generally, though, MuRFs draw on unskilled laborers who accept work that many others disdain in exchange for steady hours and pay that typically starts a dollar or so above the minimum wage.

"The work can be nasty but you feel like it's secure--people are always going to throw things away," says Algie Bullion, an Omaha worker who was laid off from his previous job as a meatpacker. Mr. Bullion, 34, says he often cautions new workers at the MuRF not to give up too quickly. "They're young, they're picking through maggots and diapers and thinking, 'Man, I can do better than this,"' he says. "But I tell them, 'Money is money, and if you haven't got the skills and education, you aren't going to do any better than this."'

Even so, turnover at some MuRFs runs 100% a year, and it is easy to see why. At the Omaha facility, a hangar-like warehouse at the city's edge, trucks dump incoming garbage on a vast "tip floor." Front-end loaders then feed the rubbish to machines that spit the refuse onto a conveyor belt known as the "trash line." Here, a half-dozen workers reach into a belt-high trough of garbage, plucking out bags of recyclables, or loose cans and bottles, and tossing them into bins and chutes for further sorting. Between loads, they use snow shovels to heft trash that has spilled off the belt and onto the floor.

On a recent day, following a rainstorm, the trash formed a wet sludge of soaked newspapers, mud-streaked bottles and cans, and burst bags extruding rotten meat, corn cobs, crushed dolls, tampons, bleach bottles, soiled kitty litter and half-empty cans of pet food. A faint drizzle of trash particles sprinkled down from tall machines that spewed still more garbage onto the line.

"When the trash is slimy, it's heavy and hard to grab hold of," says Maurice Davis, wrestling loose a sodden pile of pizza cartons. "On days like this, I feel like I'm some kind of wet rat rummaging around at the bottom of a dump."

Like other workers, though, the 33-year-old Mr. Davis says he has become inured to the filth and barely notices the odor, which is overpowering to a first-time visitor. "I used to think I was going to faint from the stink," he says. Sucking through his nostrils, he adds with a smile: "Now, I tell myself that it smells like money."

The money, however, isn't great. Employees at the Omaha facility start at $5.75 an hour and almost all top out at a dollar more than that. Temporary workers, who make up about a third of the 35-person operation, are paid $5 an hour, without benefits. They are hired permanently with benefits if they stick to the job for three months.

But few temps are assigned to the "trash line" because the work there tends to make them quit quickly, a supervisor says. One common problem: The conveyor belt causes slight motion sickness, which combines with the odor to induce nausea in newcomers. "The mix can create a unique aroma," says supervisor Jim Kemp.

The "sort line," where most newcomers work instead, isn't as pungent. Here, workers are placed between magnets and tumblers that separate out the recyclables. They perform tasks the machines can't, such as sorting glass and plastic by type and color. The work is fast-paced and nerve-jangling, punctuated by the constant smashing of glass. It also requires intense concentration so that nothing slips past.

Valentine Red says the rapid, repetitive labor often intrudes on his dreams. "I get to work tired because I've been working all night in my sleep," says the Philippine-born sorter, one of many immigrants working at MuRFs nationwide.

At the Omaha plant, which is run by Waste Management Inc., a unit of WMX Technologies Inc., workers wear steel-toed boots, hard hats and safety glasses. Gloves, arm guards and earplugs are optional, and many workers go without so they can talk with others and get a better grip on the trash. This can leave them exposed to hazards such as used hypodermic needles, bleach and smoldering ashes from household stoves. Workers also complain about the peculiar and often unpleasant items that sometimes surface: rats, dead pets, sex toys, used condoms, live snakes. In summer the trash can be especially rank--particularly if it has been by the curb or on the tip floor for a few days. In winter, many MuRFs are extremely cold, or dusty if the doors are closed to keep out the chill.

Yet, as with many other fast-growing job sectors, there has been little independent study or monitoring of MuRFs (the Bureau of Labor Statistics doesn't yet have categories to collect specific data on recycling workers and many others in new environmental fields). European studies have found high rates of skin, respiratory and intestinal problems among recycling workers. Other hazards include back and repetitive-strain injuries, needle sticks, and lacerations from cans and glass.

"There's no question that many of these facilities remain primitive in terms of safety," says Eileen Berenyi of Governmental Advisory Associates Inc., a New York-based consulting firm that is one of the few groups in America to collect data on MuRFs. She adds that the industry is extremely volatile and varied, with large, well-established facilities generally taking precautions that smaller MuRFs may not.

Iowa's Storm Lake MuRF, for instance, was cited this year by the state's Occupational Safety and Health Administration for a range of violations: inadequate safety gear, exposing workers to excessive noise and unlabeled hazardous chemicals, and failing to train workers to guard against "blood-borne pathogens" that can cause diseases such as hepatitis. The company was fined $1,320--typical of the small penalties OSHA usually doles out. Ellsworth Jeppeson, the plant's general manager, characterizes the citations as "minor stuff that we didn't even know we were supposed to be doing."

Most workers also shrug off the safety dangers of their work, which are, after all, common to the farm or slaughterhouse labor they have done before. And most have made their peace as well with the stigma of working in garbage, which causes neighbors to steer clear of them when they shop on their way home from work, and family members to insist that they strip off their clothes at the door.

"It used to bother me that I'd get home and my kids would say, 'Daddy, you stink!'" says Mr. Davis, the Omaha worker. "Now I tell them, 'Yeah, but you never say that on Fridays when I come home with a pocket full of cash.'"